1. Field of the Invention
The invention relates to a prosthetic knee joint, more particularly to a prosthetic knee joint that can effectively prevent a prosthesis wearer from falling backward when walking down an inclined surface.
2. Description of the Related Art
Referring to FIG. 1, a conventional artificial knee joint having a minimum knee angle, as disclosed in Taiwanese Patent No. M284363, includes a knee seat 11 attached to a residual thigh (not shown) and having a bottom end formed with a mounting recess 111, a support frame 11′ attached to a prosthetic lower leg (not shown), a driving member 12 disposed pivotally in the mounting recess 111 by means of a pivot pin 123, two links 13, 14 having lower ends connected pivotally to the support frame 11′, a cushion device consisting of two rubber blocks 15 disposed in the mounting recess 111 and between the knee seat 11 and the driving member 12, two bearing members in the form of unidirectional bearings 16, two pivot pins 17 extending respectively through upper ends of the links 13, 14 and journalled respectively within two mounting holes 121, 122 in the driving member 12 by the bearing members, and two pin-locking members 18 sleeved respectively and rotatably on the pivot pins 17. Each unidirectional bearing 16 includes a plurality of angularly equidistant L-shaped projections 161, a plurality of rollers 162, and a plurality of unitary resilient members 163.
Although the aforementioned artificial knee joint can achieve its intended purpose, there is a need to provide an artificial knee joint with a more simple structure and that operates to help prevent a wearer from falling when walking down an inclined surface.